In conventional electrical power distribution systems for distributing power to street lighting and other types of public lighting, several lighting systems are typically powered off of a central high voltage step-down distribution transformer. One problem with this arrangement is that each lighting system is typically connected to the high voltage distribution transformer over a different length of wire ran. Because the wire runs are of different length, each wire run therefore introduces a different voltage drop. Accordingly, each lighting system will receive a different voltage level. This problem is typically overcome by using an additional set of low voltages step-down transformers located close to the loads. By selecting an appropriate tap on each low voltage transformer, the voltage for each lighting system can be set to a desired level.
What is needed is an electrical power distribution system which can regulate the voltage delivered to various loads and systems without the need for the low voltage transformers. What is also needed is an electrical distribution system which can properly vary the voltage for various conditions such as supplying a starting voltage to properly ignite and maintain the arc in luminaires and then applying a reduced voltage once a warm-up period is finished. What is also needed is a system which can control the illumination levels for varying requirements dependant on public use and availability of natural, ambient light. Finally, what is needed is a means of controlling the power used as a demand-side management tool, in a conventional or deregulated environment, to provide a savings in electrical consumption.